Removable lid and floating pivot

ABSTRACT

A semiconductor processing system includes a chamber adapted to process a wafer, the chamber having an opening to facilitate access to the interior of the chamber. The system has a lid coupled to the chamber opening, the lid having an open position and a closed position. An actuator is connected to the lid to move the lid between the closed position and the open position. The system may include a floating pivot coupled to the lid and the actuator to align the lid with the opening when the lid closes.

CLAIM OF PRIORITY

This application is a Divisional of U.S. patent application Ser. No.09/764,605, filed Jan. 17, 2004, now U.S. Pat. No. 6,609,632.

BACKGROUND

This invention relates to apparatus and methods of providing an actuatedlid for a process chamber.

In many semiconductor-manufacturing processes, substrates are processedin a series of one or more phases. For example, substrates can undergo apre-heating phase during which the substrate is heated to an initialtemperature before the substrate is loaded completely into a processingchamber and processed with a prescribed heating cycle. To achieve therequired device performance, yield, and process repeatability, theprocessing of a substrate such as a semiconductor wafer is strictlycontrolled inside a process chamber.

Generally, a process chamber has a chamber body enclosing components ofthe process chamber. The-process chamber typically maintains vacuum andprovides a sealed environment for process gases during substrateprocessing. On occasions, the process chamber needs to be periodicallyaccessed to cleanse the chamber and to remove unwanted materialscumulating in the chamber. To support maintenance for the processchamber, an opening is typically provided at the top of the processchamber that is sufficiently large to provide access to the internalcomponents of the process chamber.

To support these conflicting requirements, a lid is used to help theprocess chamber to provide a sealed environment for the processing gasesduring substrate processing by mating with the process chamber andincorporating an elastomeric seal between the lid and the processchamber, and to allow access to the inner chamber. Typically, a lidprovides access to the components inside the chamber, and shields theoperator from exposure to high temperatures during system operation. Thelid generally remains closed during most process steps unless thechamber is opened, for example, to perform a preventive maintenancechamber cleaning, thereby breaking the vacuum and bringing the chamberto atmospheric pressure. Certain lids are manually dismounted andremoved from the chamber before the chamber can be accessed. In othercases, lid hinges connect the lids to the chambers, and these hingestypically include locking ratchets to prevent the lids fromunintentional collapses or closures that can slam the lids into thechambers with great force.

Originally, the lids were small and were easily handled by operators. Asthe chamber size increases to handle larger substrates, the lidsincrease in size. At present, lids have become relatively heavy, makingopening and closing of the lids relatively difficult. Further, whenclosing a large, heavy lid, it is difficult to properly align the lid toobtain a proper seal.

SUMMARY

In one aspect, a semiconductor processing system includes a chamberadapted to process a wafer, the chamber having an opening to facilitateaccess to the interior of the chamber. The system has a lid coupled tothe chamber opening, the lid having an open position and a closedposition. An actuator is connected to the lid to move the lid betweenthe closed position and the open position. The system may optionallyinclude a floating pivot coupled to the lid and the actuator to alignthe lid with the opening when the lid closes.

Implementations of the above aspect may include one or more of thefollowing. A fixed pivot screw may be connected to the lid and theactuator. A guide link may be connected to the fixed pivot screw. A loadlink can be connected to the floating pivot screw. A guide shaft can berotatably connected to the load link. The system also includes a drivepivot positioned at one end of the load link, and a rod extending fromthe actuator to the drive pivot can drive the lid. A support bracket canbe provided to mount the actuator to the chamber body. The actuator canbe air actuated or (hydraulically) actuated. Alternatively, the actuatorcan be motorized.

In another aspect, a floating pivot to automatically align a lid to abody of a semiconductor processing chamber includes a load link havingfirst and second portions; a flanged bearing positioned between thefirst and second portions of the bearing; and a self-centering springpositioned around the perimeter of the bearing.

Implementations of the above aspect may include one or more of thefollowing. The pivot can include a tension shim positioned between theload link and the bearing.

A pivot screw can be used to tighten the bearing. The self-centeringspring can be an O-ring, leaf springs, coil springs, or any combinationsthereof. A lid can be connected to a first end of the load link. Achamber body can be connected to a second end of the load link. Theself-centering spring can be an elastomeric separator. Theself-centering spring allows radial movements, axial movements, or bothradial and axial movements. The self-centering spring also allowsself-centering of the lid to the chamber body.

Advantages of the system may include one or more of the following. Thesystem provides a removable lid that covers and seals an opening in thechamber when closed. The lid can also be selectively opened to provideaccess to the interior of the process chamber so that components insidethe chamber may be removed for cleaning, repair or maintenance. Whenclosed, the lid is properly aligned relative to the other processingcomponents to facilitate repeatability and accuracy of the process.

The system supports a variety of instrumentation and devices on top ofthe lid while maintaining a small footprint by integrating morecomponents onto the lid. The system operates even when the lidcomponents cause the lid center of mass to be shifted or cantileveredbehind the chamber without suffering from misalignment problems.Further, the lid with components mounted on top of the lid is easy touse, simple to assemble, reliable and inexpensive.

Other features and advantages will become apparent from the followingdescription, including the drawings and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows a cross sectional view of one embodiment of an actuatedlid assembly in a closed position.

FIG. 1B shows the assembly of FIG. 1A in its open position.

FIG. 2 shows a cross sectional view of the floating pivot.

FIG. 3 shows a multi-chamber wafer processing system.

FIG. 4 shows an exemplary a system for delivering for liquid and vaporprecursors having an actuated lid.

DESCRIPTION

FIG. 1A shows an actuated lid assembly 100 in a closed position, whileFIG. 1B shows the assembly 100 in its open position. Referring now toFIGS. 1A–1B, a chamber body 102 is adapted to receive a wafer forprocessing. The chamber body 102 is selectively sealed through a chamberlid 104. Further, each side of the lid 104 is rotatably connected to aguide link 108 through a fixed pivot screw assembly 108A. Each side ofthe lid 104 is also rotatably connected to a load link 110 through afloating pivot screw assembly 110A. The floating pivot screw assembly110A is shown in more detail in FIG. 2. The guide link 108 and the loadlink 110 pivotably move about guide shafts 109A and 109B.

The load link 110 is connected to a cylinder rod 118 at a drive pivot111. An air cylinder 112 actuates cylinder rod 118. The air cylinder 112is connected to a support bracket 116 through a trunnion 114. Thesupport bracket 116 in turn is attached to the chamber body 102.Although the cylinder 112 is used in the embodiment of FIGS. 1A–1B, avariety of driving mechanisms such as a hydraulic cylinder, acontrollable motor or equivalent can be used. For example, a steppermotor and a suitable gear drive can move the lid in controlledincrements between the open and closed positions.

To move from the open position to the closed position, the air cylinder112 is depressurized, causing the cylinder rod 118 to extend and drivingthe drive pivot 111. The drive pivot 111 then applies rotational forceto be directed against the drive shaft, causing it to pivot. This forcesthe chamber lid 104 and guide link 108 to rotate about the guide shafts109A and 109B, causing the lid 104 to close. As lid closes, alignment ismaintained between the chamber lid 104 and chamber 102 to effect avacuum seal.

FIG. 1B shows the lid assembly 100 in its open position. To move fromthe closed position to the open position, the air cylinder 112 ispressurized, causing the cylinder rod 118 to contract and driving thedrive pivot 111. The drive pivot 111 then applies rotational force to bedirected against the drive shaft, causing it to pivot. This forces thechamber lid 104 and guide link 108 to rotate about the guide shafts 109Aand 109B, causing the lid 104 to open.

FIG. 2 shows a floating pivot that allows the lid 104 and the chamberbody 102 to be aligned. The floating pivot of FIG. 2 has a plain bearing222 with a flange positioned between a first portion of the load link 10and a second portion of the load link 110. The bearing 222 is secured tothe first and second portions of the load link 110 through a pivot screw202 and one or more tension shims 220.

The pivot axis about which load link 110 arm rotates is allowed somedegree of freedom through a self-centering spring. In this embodiment,the self-centering spring includes two elastomeric separators 208 and210. In one embodiment, the elastomeric separators 208–210 are O-ringsthat center the plain bearing 222 with the flange inside a housinginside the load link 110. The O-ring plain bearing 222 is located nearthe O-rings 208–210 , and due to the O-ring 208–210 's elastic property,the bearing 222 is allowed to be displaced laterally around the axis ofrotation some small amount to accommodate alignment between the chamberlid 104 and the chamber body 102 as the lid 104 closes. The elastomericmaterial includes physical characteristics permitting the first andsecond portions of the load link 110 to rotate and shift laterally withrespect to each other. The elastic property of the elastomericseparators 208–210 , in this case the O-rings, serves as a “selfcentering spring” acting about the pivot axis. This allows the pivotaxis to “float”, thereby providing a self-alignment and self-centeringfeature between the chamber body 102 and the lid 104. Further, the oneor more elastomeric separators allow radial movements, axial movements,or both radial and axial movements, in addition to supportingself-centering. The “self centering spring” is not necessarily limitedto an elastomer or an “o-ring”. Any number of “self centering spring”designs could be implemented to perform the same function as theelastomeric “o-rings”. For example, a plurality of leaf or coil springscould be arrayed radially about the longitudinal axis of the pivot screw202 and used in either tension or compression to perform the samefunction as the elastomeric o-rings.

The elastomeric material is a rubber-like material having broadperformance characteristics over a wide temperature range. Materialsthat will perform under these conditions will be, for example, but notlimited to, polyether polyurethanes, polyester polyurethanes, rubbers,thermoplastic urethanes, thermoplastic elastomers, any copolymer ofthese or other materials, and any other such elastomeric material thatcan be cast, compression molded, injection molded, extruded or any othertype of manufacturing process. The materials may also use a form ofreinforcing such as, but not limited to, fibers, cloths, or fillers.

Due to the physical characteristics of the elastomeric material, theload link 110 can now pivot on a floating pivot axis. In other words,the opposite first and second sides of the elastomeric material canshift laterally and rotate simultaneously with respect to each otherduring pivoting of the load link 110.

Referring now to FIG. 3, a multi-chamber semiconductor processing system800 is shown. The processing system 800 has a plurality of chambers 802,804, 806, 808 and 810 adapted to receive and process wafers 842.Controllers 822, 824, 826, 828 and 830 control each of the chambers 802,804, 808 and 810, respectively. Additionally, a controller 821 controlsanother chamber, which is not shown for illustrative purposes.

Each of chambers 802–810 provides a lid 104 on the chamber body 102.During maintenance operations, the lid 104 can be actuated into the openposition so that components inside the chamber body 102 can be readilyaccessed for cleaning or replacement as needed.

The chambers 802–810 are connected to a transfer chamber 840 thatreceives a wafer (not shown). The wafer rests on top of a robot blade orarm (not shown). The robot blade receives the wafer from an outsideprocessing area.

The transport of wafers between processing areas entails passing thewafers through one or more doors separating the areas. The doors can beload lock chambers 860–862 for passing a wafer-containing container orwafer boat that can hold about twenty-five wafers in one embodiment. Thewafers are transported in the container through the chamber from onearea to another area. The load lock can also provide an air circulationand filtration system that effectively flushes the ambient airsurrounding the wafers.

Each load lock chamber 860 or 862 is positioned between sealed openings,and provides the ability to transfer semiconductor wafers betweenfabrication areas. The load locks 860–862 can include an air circulationand filtration system that effectively flushes the ambient airsurrounding the wafers. The air within each load lock chamber 860 or 862can also be purged during wafer transfer operations, significantlyreducing the number of airborne contaminants transferred from onefabrication area into the other. The load lock chambers 860–862 can alsoinclude pressure sensors that take air pressure measurements for controlpurposes.

During operation, a wafer cassette on a wafer boat is loaded at openingsin front of the system to a load lock through the load lock doors. Thedoors are closed, and the system is evacuated to a pressure as measuredby the pressure sensors. A slit valve (not shown) is opened to allow thewafer to be transported from the load lock into the transfer chamber.The robot blade takes the wafer and delivers the wafer to an appropriatechamber. A second slit valve opens between the transfer chamber andprocess chamber, and wafer is brought inside the process chamber.

Containers thus remain within their respective fabrication areas duringwafer transfer operations, and any contaminants clinging to containersare not transferred with the wafers from one fabrication area into theother. In addition, the air within the transfer chamber can be purgedduring wafer transfer operations, significantly reducing the number ofairborne contaminants transferred from one fabrication area into theother. Thus during operation, the transfer chamber provides a high levelof isolation between fabrication stations.

FIG. 4 shows an exemplary an apparatus 40 for liquid and vapor precursordelivery using the system 100. The apparatus 40 includes a chamber 44such as a CVD chamber. The chamber 40 includes a chamber body 102 thatdefines an evacuable enclosure for carrying out substrate processing.The chamber body 102 has an opening that is covered by the actuated lid104. During operation, the lid 104 is in its closed position to seal thechamber body 102 from ambient environment. For maintenance purposes, thelid 104 can be actuated into the open position so that components insidethe chamber body 102 can be readily accessed for cleaning or replacementas needed.

The chamber body has a plurality of ports including at least a substrateentry port that is selectively sealed by a slit valve and a side portthrough which a substrate support member can move. The apparatus 40 alsoincludes a vapor precursor injector 46 connected to the chamber 44 and aliquid precursor injector 42 connected to the chamber 40.

In the liquid precursor injector 42, a precursor 60 is placed in asealed container 61. An inert gas 62, such as argon, is injected intothe container 61 through a tube 63 to increase the pressure in thecontainer 61 to cause the copper precursor 60 to flow through a tube 64when a valve 65 is opened. The liquid precursor 60 is metered by aliquid mass flow controller 66 and flows into a tube 67 and into avaporizer 68, which is attached to the CVD chamber 71. The vaporizer 68heats the liquid causing the precursor 60 to vaporize into a gas 69 andflow over a substrate 70, which is heated to an appropriate temperatureby a susceptor to cause the copper precursor 60 to decompose and deposita copper layer on the substrate 70. The CVD chamber 71 is sealed fromthe atmosphere with exhaust pumping 72 and allows the deposition tooccur in a controlled partial vacuum.

In the vapor precursor injector 46, a liquid precursor 88 is containedin a sealed container 89 which is surrounded by a temperature controlledjacket 100 and allows the precursor temperature to be controlled towithin 0.1° C. A thermocouple (not shown) is immersed in the precursor88 and an electronic control circuit (not shown) controls thetemperature of the jacket 100, which controls the temperature of theliquid precursor and thereby controls the precursor vapor pressure. Theliquid precursor can be either heated or cooled to provide the propervapor pressure required for a particular deposition process. A carriergas 80 is allowed to flow through a gas mass flow controller 82 whenvalve 83 and either valve 92 or valve 95 but not both are opened. Alsoshown is one or more additional gas mass flow controllers 86 to allowadditional gases 84 to also flow when valve 87 is opened, if desired.Additional gases 97 can also be injected into the vaporizer 68 throughan inlet tube attached to valve 79, which is attached to a gas mass flowcontroller 99. Depending on its vapor pressure, a certain amount ofprecursor 88 will be carried by the carrier gases 80 and 84, andexhausted through tube 93 when valve 92 is open.

After the substrate has been placed into the CVD chamber 71, it isheated by a heater. After the substrate has reached an appropriatetemperature, valve 92 is closed and valve 95 is opened allowing thecarrier gases 80 and 84 and the precursor vapor to enter the vaporizer68 through the attached tube 96 attached tube 96. Such a valvearrangement prevents a burst of vapor into the chamber 71. The precursor88 is already a vapor and the vaporizer is only used as a showerhead toevenly distribute the precursor vapor over the substrate 70. After apredetermined time, depending on the deposition rate of the copper andthe thickness required for the initial copper deposition, valve 95 isclosed and valve 92 is opened. The flow rate of the carrier gas can beaccurately controlled to as little as 1 sccm per minute and the vaporpressure of the precursor can be reduced to a fraction of an atmosphereby cooling the precursor 88. Such an arrangement allows for accuratelycontrolling the copper deposition rate to less than 10 angstroms perminute if so desired. Upon completion of the deposition of the initialcopper layer, the liquid source delivery system can be activated andfurther deposition can proceed at a more rapid rate.

The present invention has been described in terms of severalembodiments. The invention, however, is not limited to the embodimentdepicted and described. For instance, the radiation source can be aradio frequency heater rather than a lamp. Hence, the scope of theinvention is defined by the appended claims.

1. A semiconductor processing system, comprising: a chamber adapted toprocess a wafer, the chamber having an opening to facilitate access tothe interior of the chamber; a lid coupled to the chamber opening, thelid having an open position and a closed position; an actuator coupledto the lid to move the lid between the closed position and the openposition; and a self-centering floating pivot coupled to the lid and theactuator to align the lid with the opening when the lid closes.
 2. Thesystem of claim 1, further comprising a fixed pivot coupled to the lidand the actuator.
 3. The system of claim 2, further comprising a guidelink coupled to the fixed pivot.
 4. The system of claim 1, furthercomprising a load link coupled to the floating pivot.
 5. The system ofclaim 1, further comprising a guide shaft rotatably coupled to the loadlink.
 6. The system of claim 1, further comprising a drive pivotpositioned at one end of the load link.
 7. The system of claim 6,further comprising a rod extending from the actuator coupled to thedrive pivot to move the lid.
 8. The system of claim 1, furthercomprising a support bracket coupled to the actuator and the chamberbody.
 9. The system of claim 1, wherein the actuator is air actuated orhydraulically actuated.
 10. The system of claim 1, wherein the actuatoris motorized.
 11. A semiconductor processing system, comprising: achamber adapted to process a wafer, the chamber having an opening tofacilitate access to the interior of the chamber; and a lid coupled tothe chamber opening, the lid having an open position and a closedposition, the open and closed positions being moved translationally in asubstantially parallel manner relative to the opening; and an actuatorcoupled to the lid to move the lid between the closed position and theopen position.
 12. The system of claim 11, further comprising aself-centering floating pivot to automatically align the lid to the bodyof the chamber.
 13. The system of claim 12, wherein the pivot furthercomprises: a load link having first and second portions; a bearingpositioned between the first and second portions of the bearing; and aself-centering spring coupled to the perimeter of the bearing.
 14. Asemiconductor processing system, comprising; a chamber adapted toprocess a wafer, the chamber having an opening to facilitate access tothe interior of the chamber; a lid coupled to the chamber opening, thelid having an opened position and a closed position; an actuator coupledto the lid to move the lid between closed position and the openedposition; and a floating pivot coupled to the lid and the actuator toalign the lid with the opening when the lid closes; wherein the actuatoris motorized.
 15. A semiconductor processing system, comprising; achamber adapted to process a wafer, the chamber having an opening tofacilitate access to the interior of the chamber; and a lid coupled tothe chamber opening, the lid having an open position and a closedposition, the opened and the closed positions being moved horizontallyin a substantially parallel manner relative to the opening; and aactuator coupled to the lid to move the lid between the closed positionand the opened position; a floating pivot to automatically align the lidto the body of the chamber; wherein the pivot further comprises: a loadlink having first and second portions; a bearing positioned between thefirst and second portions of the bearing; and self-centering springcoupled to the perimeter of the bearing.